Multiple exposure imaging apparatus

ABSTRACT

A machine for automatically making a plurality of superposed exposures optical input from a moving object cylinder carrying a document to a synchronously moving transparent electro-conductive image cylinder for forming the images. Internal to both the cylinders is an optical system for projecting contiguous portions of the object onto a plurality of locations on the image cylinder each in superposed registration. The optical systems are aligned such that a presentation of a point from the object to the image cylinder at one portion of the surface is repeated at the same portion of the surface after the surface has moved from its original position. The optical systems each have a skewed lens and a plane and roof mirror for projecting transferable images without keystone distortion. An embodiment uses the optical reimaging system for forming photoelectrophoretic images.

[451 Nov. 21, 1972 3,152,528 10/1964Pendry..........................355/3 Primary Examiner-Samuel S.Matthews Assistant Examiner-Kenneth C. Hutchison Attorney-James J.Ralabate, David C. Petre and Barry J. Kesselman [57] ABSTRACT A machinefor automatically making a plurality of superposed exposures opticalinput from a moving object cylinder carrying a document to'asynchronously moving transparent electro-conductive image cylinder forforming the images. lntemal to both the cylinders is an optical systemfor projecting contiguous portions of the object onto a plurality oflocations on the image cylinder each in superposed registration. Theoptical systems are aligned such that a presentation of a point from theobject to the image cylinder at one portion of the surface is repeatedat the same portion of the surface after 'the surface has moved from itsoriginal position. The optical systems each have a skewed lens and aplane and roof mirror for projecting transferable images withoutkeystone distortion. An embodiment uses the optical re-imaging systemfor forming photoelectrophoretic images.

APPARATUS [72] Inventors: Sanford G. Hoffman, Rochester; Earl V.Jackson, Penfield; Gary K. Starkweather; Edwin Zucker, both ofRochester, all of NY.

Xerox Corporation, Rochester, N.Y.

Dec. 22, 1969 .355/51, 355/4, 355/8, 35 5/46 .G03b 27/32, 603g 15/00.355/3, 4, 8, 32, 46-51, 355/54 References Cited UNITED STATES PATENTSUnited States Patent Hoffman et al.

[54] MULTIPLE EXPOSURE IMAGING [7 3] Assignee:

[22] Filed:

[21]- Appl. No.: 887,453

[52] US. Cl.

[51] lntrCl.

[58] Field of Search...............

725 8/1970 Schaefferm;..................355/8 242 2/1969Mihajlov.................355/3 UK 864 2/1971 Carreira 081 8/1971Egnaczak...................355/8 X 466 5/1961 Kaprelian .....355/4 X 20Claims, 3 Drawing Figures PATENTEnnum m: 3.703.335

sum 1 or 2 SAN FORD G. HOFFMAN EARL V. JACKSON f INVENTORS I GARY K.STARKWEATHER' EDWIN ZUCKER 1 ITTOR/VEY 1 MULTIPLE EXPOSURE IMAGINGAPPARATUS This invention relates to imaging machines and moreparticularly to machines employing multiple exposure techniques.

Since the new invention of photoelectrophoresis was disclosed forforming black and white or full color images, various machineembodiments have been envisioned to accommodate this imaging techniquein an automated machine environment. The basic inventions are describedin U.S. Pat. Nos. 3,383,993; 3,384,565 and 3,384,566; They disclosehow'to produce a visual image at one or both of two electrodes betweenwhich photoelectrophoretic particle suspensions are placed. Theparticles are photosensitive and appear to undergo a net change incharge polarity or a polarity alteration by interaction with one of theelectrodes upon exposure to activating electromagnetic radiation.Mixtures of two or more differently colored particles can secure variouscolors of images. The particles will migrate from one of the electrodesunder the influence of an electric field when struck with energy of awavelength within the spectral response curve of the colored particles.

A continuous imaging machine was: disclosed in U.S. Pat. No. 3,427,242which depicts apparatus for forming continuous images fromphotoelectrophoretic suspensions by projection of an original utilizinga system for scanning an object and passing the image light raystwicethrough the transparent surface of a cylindrical electrode.

The practical image formation from the process disclosed above isenhanced in many cases by subjecting the photoelectrophoretic particlesto imaging conditions more than once. By re-subjecting thephotoelectrophoretic imaging particle suspension to substantially thesame image light pattern and an electric field more than once, the finalimage formed is enhanced by the removal of particles from areas wherethere was insufficient illumination to previously cause'migration ofparticles from one electrode to another. If a machine such as thatdisclosed in U.S. Pat. No. 3,427,242 were to attempt to enhance imagesby re-exposure under imaging conditions a second time using thesameprojection system, it would require a second revolution of the imageforming electrode in that machine. This would reduce the speed andefficiency of the machine by half or more depending on the number ofimaging passes determined best for full image enhancement.

Therefore, it is an object of this invention to improve apparatus forautomatically producing images. Another object of this invention is tosubject photosensitive materials to a plurality of exposures within onecycle of imaging apparatus. Yet another object of this invention is toprovide multiple image projection means for forming registered images onmoving plates. Still another object is to improve multicolor imagingsystems.

These and other objects of this invention are accomplished by using atransparent cylindrical image carrying member that rotates through apath interfacing with a series of components utilized for automatedimage formation. Photoresponsive material is coated on the outer surfaceof the transparent cylindrical member and projection of images occurs ata plurality of fixed positions around its periphery. Acylindrical'document platen is rotated in a coordinated manner with thecylindrical transparent image carrying member. A coordinated opticalsystem projects contiguous portions of the moving document ontocontiguous portions of the moving image carrying member. The projectionsare matched such that the same portion of the document projected to theimage carrying cylindrical member ata first position are matched atsubsequent positions in registration so that like portions of theprojected object are projected to the same spot on the moving imagecarrying electrode at each of the image planes of the plurality of theoptical projection systems.

The invention herein is described and illustrated in a specificembodiment having specific components listed for carrying out thefunctions of the apparatus. Nevertheless, the invention need not bethought of as being confined to such a specific showing and should beconstrued broadly within the scope of the claims. Any and all equivalentstructures known to those skilled in the art can be substituted forspecific apparatus disclosed as long as the substituted apparatusachieves a similar function. It may be that other processes or apparatuswill be invented having similar needs to those fulfilled by theapparatus described and claimed herein and it is the intention herein todescribe an invention for use in apparatus other than the embodimentshown. j

These and other objects and advantages will become apparent to thoseskilled in the art after reading the following description taken inconjunction with the accompanying drawings wherein:

FIG. 1 is a schematic isometric representation of an embodiment of amachine for forming photoelectrophoretic images in accordance with theinvention herein;

FIG. 2 schematically illustrates a mechanism for varying themagnification of the optical system for image magnification matching,and

FIG. 3 diagramatically shows an unfolded system for re-exposingmagnified portions of the object cylinder on an image cylinder. I

There are certain terms of art used in conjunction with thephotoelectrophoretic imaging process (of FIG. 1) which should bedefined. The injecting electrode is so named because it is thought toinject electrical charges into activated photosensitive particles duringimaging. The term photosensitive for the purpose of this disclosurerefers to the property of a particle which, once attracted to theinjecting electrode, will alter its polarity and migrate away from theelectrode under the influence of an applied electric field when exposedto activating electromagneticradiation. The term suspension may bedefined as a system having solid particles dispersed in a solid, liquidor gas. Nevertheless, the suspension used in the disclosure herein is ofthe general type having a solid suspended in a liquid carrier. The termimaging electrode is used to describe that electrode which interactswith the injecting electrode through the suspension and which oncecontacted by activated photosensitive particles will not injectsufficient charge into them to cause them to migrate from the imagingelectrode surface. The imaging electrode is covered with a dielectricsurface composed of a material having a volume resistivity preferably inthe order of 10 or greater ohm-cm and a conductive core member which ispreferably a resilient material such as electrically conductive rubberused to give flexibility to the imaging electrode.

For photoelectrophoretic imaging to occur it is thought that thesesteps, not necessarily listed in the sequence that they occur, takeplace: (1) migration of the particles toward the injecting electrode dueto the influence of an electric field, (2) the generation of chargecarriers within the particles when struck by activating radiation withintheir spectral response curve; (3) particle deposition on or near theinjecting electrode surface; (4) phenomena associated with the formingof an electrical junction between theparticles and the injectingelectrode; (5) particle charge exchange with the injecting electrode;(6) electrophoretic migration toward the imaging electrode; (7) particledeposition on the imaging electrode. This leaves an optically positiveimage on thecontacted surface of the injecting electrode.

The schematic representation of FIG. 1 shows a photoelectrophoreticimaging apparatus having an injecting electrode 1 with a coating 2 oftransparent electrically conductive material such as tin oxide on theoutside surface of a transparent glass member. Such a combination iscommercially available under the name of NESA glass from PittsburghPlate Glass Company of Pittsburgh, Pa. However, other electricallyconductive coatings over transparent substrates are suitable for useherein. At a first imaging area 10 an imaging electrode 12 interfaceswith the outer surface of the injecting electrode 1. The imagingelectrode carries imaging suspension 13 from the suspension supplyhousing 14 via a suspension application system having a metering rolllSand an applicator roll 16. The imaging suspension is applied to thesurface of the injecting electrode between the injecting electrode 1 andthe imaging electrode 12 at the first imaging area 10.

The imaging electrode 12 has a high dielectric surface 18 overcoated ona conductive flexible inner core 20 which is preferably a resilientmaterial of conductive rubber or the like. A second imaging electrode 22interfaces with the outer surface of the injecting electrode 2 at asecond imaging area 24. Both of the imaging electrodes are connected tothe negative terminal of an electrical source 25. The injectingelectrode 1 is shown schematically connected to ground so that a fieldexists between the two imaging electrodes on the one hand and theinjecting electrode on the other as is required for thephotoelectrophoretic imaging process. In actual practice the electrodesmay be coupled to separate sources and even energized to differentpotentials. The second imaging electrode 22 has a fluid sprayer 32operatively associated with it to spray carrier material onto thesurface. This aids in selectively removing particles of the suspensionfrom the outer surface of the injecting electrode under imagingconditions provided by the optical system and the. electrical source.Ithas been found that the addition of material similar to the liquidcarrier of the imaging suspension aids in the migration of particles ofthe suspension away from the injecting electrode in the second imagingarea 24.

Interfacing with the outer surface 2 of the injecting electrode 1downstream or further along the path of movement of the injectingelectrode is the transfer roller 26 and transfer support sheet 27. Thetransfer roller is electrically connected to a source 28 for causing anopposite polarity to the two imaging electrodes 20 and 22 with theirelectrical source. It is the function of the transfer electrode toelectrophoretically transfer the imaging suspension from the surface 2of the injecting electrode 1 to a support material which is used as thefinal image support media. A cleaning brush 29 is placed in contact withthe outer surface of the injecting electrode 1 to remove residualsuspension remaining on the injecting electrode after transfer has beencompleted. Similarly, cleaning brushes 30 and 31 contact the imagingelectrodes 12 and 22 respectively to clean their surfaces after theyinterface with the injecting electrode. 7

The integrated dual optical system shown herein presents superposedimagewise electromagnetic radiation at each of the plurality of imagingareas denoted by the numerals 10 and 24. The image is of contiguousportions of the document 34 placed on the document drum 36 at the objectplane of the plurality of the lenses 38 and 39. Radiation energy orillumination is supplied by light sources 40-43. The two reference lines45 and 46 shown in FIG. 1 represent the principal ray from the objectplane to the image plane of the optical system. It should be noted thatthe document 34 is maintained on a surface of the object drum 36 whichpasses through the object plane of each of the two lenses 38 and 39. Theouter surface 2 of the injecting electrode 1 moves through the imageplane of the two lenses at the imaging areas 10 and 24, respectively.The principal rays 45 and 46 shown are not the optical axes of each ofthe lenses. The optical axes in fact are shown by the reference lines 48and 49.

Within the dual optical system are equal sets of mirrors including planemirrors 50 and 51 and roof mirrors 52 and 53 shown in the respectiveoptical paths of the two lenses 38 and 39.

Although only two optical systems are shown it is possible for three ormore to be coordinated in the manner of this invention to permitmultiple imaging passes with a single revolution of the injectingelectrode past a plurality of imaging electrodes equal to the number ofcoordinated optical systems. The optical systems function to presentmultiple exposures of the document from various places of the objectdrum to various pre-selected places of the injecting electrode so thatthe same portions of the document are projected at each of the variouspre-positions on the injecting electrode.

FIG. 2 shows an alternative placement of the optical components toachieve the same results as the optical system of FIG. 1 permittingparallel placement of the lenses. Also shown is a schematicrepresentation of means for varying the distances of the variouscomponents from each other and from the object and image planes. Theapparatus illustrated enables changing the total conjugate length of thesystem. The front or rear conjugate between the object and lens and thelens and image plane is also changeable. The mirrors -63 are mounted ontwo fixed frames 64 and 66. They are rigidly locked so that the opticalrelationship between mirrors 60 and 62 on frames 64, and mirrors 61 and63 on frame 66 is fixed. The distances between the mirrors and the focalplanes of the system may be varied by any means such as the four sets ofhanging jacks 68-71 shown. The combination of jacks enables changing thetotal conjugate length between the object and image planes and a tiltingor correction for tilting of the optical system between the object andimage planes. This adjustment provides proper focusing of the objectlight rays onto the image planes. The lenses in the system are movablymaintained on the rigid frames by what is shown schematically to be alockable slide combination. A precision lens bench adjustment isaccomplished by removable tools and the lenses are locked after theadjustment. In this way each of the lenses 72 and 74 are movable alongthe principal rays 76 and 78, respectively, to vary the magnification ofthe object at the image plane.

The reason that these adjustmentsare built into the system is that themechanical and optical tolerances of manufacture are generally notadequate to ensure proper registration of the image from the secondoptical system with that previously projected from the first opticalsystem. By pre-setting the distances of the object scanning areas 79 and80 with the imaging areas 82 and 83 and nominally setting the conjugatesand focal length of the multiple imaging optical apparatus to be equal,one can use mechanisms, shown schematically here, to finally adjust forundesirable deviations in the optical system.

Another point to be noted in this figure that is different from FIG. 1is the orientation of the lenses. In FIG. -I, the lenses were positionednon-parallel with each other as well as with the principal ray. Thebenefit of the second system is that closer physical positioning of theoptical systems is achievable. The reason the lenses can be positionedparallel with each other in FIG. 2 is that the roof and plane mirrors ofone of the systems is reversed in their positions from the roof andplane mirrors of the system adjacent to it. While both plane mirrors areonthe image side of the lens in FIG. 1, only one of theplane mirrors andone of the roof mirrors are on the image side of the lenses in FIG. 2.

The lenses are offset at some angle relative to the principal rays shownin the accompanying figures in order to provide an orthogonal imagingarrangement. Keystoning occurs when the object plane, image plane, andthe plane of the lens are not parallel. The distortion causes anelongation or non-parallelism of parallel object lines. If the systemsshown in FIGS. 1 or 2 were unfolded, it would be noted that the imageplanes represented for example in FIG. 2 by the numerals 82 and 83 areparallel to their respective object planes, namely 79 and 80 and thenodal planes of the lenses 72 and 74. However, if the lenses wereperpendicular instead of skewed to the principal axes 76 and 78, asevere keystoning problem would occur. Further, the projection of theaerial images would not be tangent to the imaging planes 82 and 83. Ifthe width of the imaging slits were small, however, the images would bein focus at the image cylinder. Nevertheless, this focused image at eachof the image planes would be expanding transversely across the imagearea. The movement of any point of the image relative to the movinginjecting electrode would cause a blur and a distortion as the systemscans. Further, in this system it would result in severe lack ofregistration and resolution causing a blurred final image. To eliminatethis undesirable distortion, the lenses are tilted relative to theprincipal ray so that the plane passed perpendicularly through the lensaxis is parallel to the object plane and image plane thus beingorthogonal as mentioned above. That is to say it is parallel in theoptical sense.

One of the unique features of this three mirrored multiple imagingsystem is the ability to take two alike curved surfaces as an object andimage plane and by moving them in synchronous motion produce an image ofthe object. The image is optically suitable for transfer to become aright reading final image on a sheet of support material. The objectdrum and the image drum can be one continuous transparent cylinder ifthe magnification of the system is set for l to 1 or two separatecylinders as shown in FIG. 1. If two cylinders are used and 1 to 1magnification is desired, they are of the same diameter and aremechanically locked to be rotated at the same surface velocity making apractical multiple scanning system.

For magnifications different from 1 to l, the image cylinderradius isequal to the product of the object cylinder radius and the opticalmagnification. Angular velocity and the angle between imaging stationsare equal on both cylinders. Consider the following mathematicaldefinitions and equations:

M magnification of the image to the object t time for the objectcylinder to rotate through an angle a (see FIG. 3) t, time for the imagecylinder to rotate through an angle a, (see FIG. 3)

R= radius of the image cylinder r= radius of the object cylinder wangular velocity of the image cylinder w, angular velocity of the objectcylinder l. t n; necessary for registration in the direction of scan 2.a, a necessary to keep the object and image planes optically parallel.

The image cylinder velocity V, Rw,

3. KW, Mr w,,; (Necessary for equality of flowing aerial image velocityand moving imaging cylinder velocity) 5. substituting (3) into (4)Therefore, in a multiple slit scan system the angular velocities of theobject and image cylinders are equal for all magnifications and theradii of the cylinders are in the proportions of the magnification.

For magnifications other than 1 to l, the chord lengths, or the distancebetween the object slits and the distance between the image slits aredifferent. These relationships can be seen and better understood byreference to FIG. 3. The object drum is represented as two drums becauseof the optical relationship represented in an optically unfolded system.The radius r is shown for the drum and its angular velocity w,, isrepeated on each representation even though there is only one cylinderand one velocity. The dashed line between the object slits and the imageslits indicate the spacing relation of the slits to the lenses and toeach other. The mirrors of the system would be displaced laterallydepending on their location along the optical path. Their orientationwould not change, only their lateral position as would be seen in a planview of the system.

Depending on the size allowed for the imaging processor, a multiple ofany desired number of optical systems within reason, can be accommodatedwithin the system for multiple reinforced imaging of an object.

The optical system can be arranged externally to the cylinders and canbe aligned for radial projection thus eliminating the need for turningthe lenses as shown in FIGS. 1 and 2. Radial projections are possibleinternally if the cylinders are sufficiently large to accommodate theoptical devices.

In a 1 to l magnification system the object and image cylinders arerotating at the same surface velocity through the fixed object and imageplanes of the multiple optical systems. Because it is preferable to haveclose registration of each of the projected images, it is necessary toset the precise placement of each optical system relative to the others.Because of the aforementioned conditions the matching of images toproduce close registration from the flowing object is achieved bymeasuring the distances between the various object positions beingprojected and project them at nearly precisely the same distances alongthe imaging cylinder. For a magnified system as shown in FIG. 3, theprecise distance relationship is as important as for a 1 to 1 system. InFIG. 3 the angles a. and a are the same and the lens nodal planes areparallel to the object and image planes. The conjugate positions of thelenses are in the ratio of the radii R and r.

For this to be achieved the mirrors must be prealigned. Hence, a rigidmirror alignment device such as shown in FIG. 2 is helpful. In order tohave acceptable registration, there must be a precise magnificationmatching of the various optical systems. This is one of the reasons thatthe lenses are preferred to be movable along the optical path forchanging magnification. Another requirement for a good optical system isthat the focused image be projected tangentially to the imaging cylinderat the imaging slits. For this reason, a total conjugate variation isbeneficial. Again, this is one of the functions of the apparatus shownin FIG. 2, and the combination of lens positioning and total conjugatevariation adjustment and in obtaining a precisely registered focusedoutput. To make an optimum resolution multiple optical imaging system,the system should have equal velocity flowing images and image planes.The optical systems should be focused and precisely aligned relative toeach other with little or no distortion from keystoning. Imagemagnification of each should match the others.

While this invention has been described with reference to the structuresdisclosed herein and while certain theories have been expressed, it isnot confined to the details set forth; and this application is intendedto cover such modifications or changes as may come within the purposesof the improvements and scope of the following claims.

What is claimed is:

1. Apparatus for imaging including a single object data support means;

means to move the object data support means for supporting a document;

multiple optical means each having an object position on the object datasupport means;

image receiving cylinder means;

an image position corresponding to each of the object positions on thecylinder means;

means to rotate the cylinder means;

lens means determining an optical path between an object position andcorresponding image position; reflecting means along the optical path;

to align the multiple optical means for sequentially projecting portionsfrom the object positions in superposed relationship to thecorresponding imaging positions.

2. The apparatus of claim 1 wherein the multiple optical means areinternal to the cylinder means.

3. The apparatus of claim 2 wherein said cylinder means is transparent.

4. The apparatus of claim 1 including means to illuminate the opticalobject data support means at each of the object positions.

5. The apparatus of claim 1 wherein the roof reflecting member and theplane reflecting member are located on opposite sides of the lens means.

6. The apparatus of claim 5 wherein the roof reflecting member in one ofthe multiple optical means is on the same side of the lens means as isthe plane reflecting member of the optical means adjacent thereto.

7. The apparatus of claim 6 wherein the lens means of the multipleoptical means are parallel with each other.

8. The apparatus of claim 1 wherein the lens means are skewed relativeto the principal ray of the optical means.

9. The apparatus of claim 1 including means to move the lens means alongthe optical path.

10. The apparatus of claim 1 including means to move the lens means andreflecting means relative to the object position.

11. The apparatus of claim 1 wherein said reflecting means includes aplane reflecting member and a roof reflecting member.

12. Apparatus for imaging including cylindrical object data supportmeans;

means to move the object data support means;

multiple optical means each having an object position on the object datasupport means;

image receiving cylinder means;

an image position corresponding to each of the object positions on thecylinder means;

to rotate the cylinder means;

lens means determining an optical path between an object position andcorresponding image position; reflecting means along the optical path;

means to align the multiple optical means for sequentially projectingportions from the object positions in superposed relationship to thecorresponding imaging positions.

13. The apparatus of claim 12 wherein the cylindrical object datasupport means for maintaining multiple object positions and the cylindermeans for maintaining multiple image positions are cylinders being ofapproximately equal diameter and rotatable at approximately the samesurface velocity.

14. The apparatus of claim 13 wherein said cylindrical object datasupport means and the cylinder means for maintaining multiple imagepositions are related in size such that the radius of the cylinder meansapproximately equals the product of the object data support cylinder andthe optical magnification of the optical means, both cylinders beingrotatable at the same angular velocity.

15. The apparatus of claim 14 wherein the angular 16. Apparatus forimaging including object data support means;

means to move the object data support means;

multiple optical means each having an object position on the object datasupport means;

image receiving cylinder means;

an image position corresponding to each of the object positions on thecylinder means;

means to rotate the cylinder means;

lens means determining an optical path between an object position andcorresponding image position;

reflecting means along the optical path;

means to align the multiple optical means for sequentially projectingportions from the object positions in superposed relationship to thecorresponding imaging positions;

multiple imaging electrodes interfacing with the cylinder means at themultiple image positions;

means to couple the electrodes and the cylinder means to electricalsource means; and,

means to supply photoelectrophoretic particles between a first imagingelectrode and the cylinder means.

17. The apparatus of claim 16 including means to transfer particles fromthe cylinder means; means to couple said means to transfer to electricalsource means of a polarity different from the imaging electrodes.

18. Apparatus for imaging including 1. single object data support meansfor supporting a document having sequential areas of which are to besequentially scanned and having spaced areas, spaced in the scanningdirection, which are to be scanned concurrently;

. image receiving cylinder means;

. a first lens means located along a first optical path which extendsbetween said object data support means and said cylinder means;

. a second lens means located along a second optical path which extendsbetween said object data support means and said cylinder means, saidfirst optical path and said second optical path being spaced from eachother in the scanning direction at said object data support means, atsaid cylinder means and at said first and second lens means and LAN 5.means to cause relative movement in the scanning direction a. between adocument at said object data support means and the ends of the opticalpaths thereadjacent whereby sequential areas of the document are scannedby one of said lens means and thereafter the same sequential areas ofthe document are scanned by the other of said lens means and b. betweensaid cylinder means and the ends of the optical paths thereadjacentwhereby images may be projected from said object data support means tosaid cylinder means along the optical aths in su rposed relationship.19. he appara us as set forth in claim 18 and further including imagereflecting means along both optical paths.

20. Apparatus for imaging including 1. single object data support meansfor supporting a document having sequential areas of which are to besequentially scanned and having spaced areas, spaced in the scanningdirection, which are to be scanned concurrently;

. image receiving cylinder means;

3. a first lens means located along a first optical path which extendsbetween said object data support means and said cylinder means;

. a second lens means located along a second optical path which extendsbetween said object data support means and said cylinder means, saidfirst optical path and said second optical path being spaced from eachother in the scanning direction along their entire lengths;

5. means to cause relative movement in the scanning direction a. betweena document at said object data support means and the ends of the opticalpaths thereadjacent whereby sequential areas of the document are scannedby one of said lens means and thereafter the same sequential areas ofthe document are scanned by the other of said lens means and b. betweensaid cylinder means and the ends of the optical paths thereadjacentwhereby images may be projected from said object data support means tosaid cylinder means along the optical paths in superposed relationshipand c. reflecting means along each optical path including a roof mirroron one side of the lens means and a mirror on the other side of the lensmeans.

1. single object data support means for supporting a document havingsequential areas of which are to be sequentially scanned and havingspaced areas, spaced in the scanning direction, which are to be scannedconcurrently;
 1. Apparatus for imaging including a single object datasupport means; means to move the object data support means forsupporting a document; multiple optical means each having an objectposition on the object data support means; image receiving cylindermeans; an image position corresponding to each of the object positionson the cylinder means; means to rotate the cylinder means; lens meansdetermining an optical path between an object position and correspondingimage position; reflecting means along the optical path; to align themultiple optical means for sequentially projecting portions from theobject positions in superposed relationship to the corresponding imagingpositions.
 1. Apparatus for imaging including a single object datasupport means; means to move the object data support means forsupporting a document; multiple optical means each having an objectposition on the object data support means; image receiving cylindermeans; an image position corresponding to each of the object positionson the cylinder means; means to rotate the cylinder means; lens meansdetermining an optical path between an object position and correspondingimage position; reflecting means along the optical path; to align themultiple optical means for sequentially projecting portions from theobject positions in superposed relationship to the corresponding imagingpositions.
 1. single object data support means for supporting a documenthaving sequential areas of which are to be sequentially scanned andhaving spaced areas, spaced in the scanning direction, which are to bescanned concurrently;
 2. image receiving cylinder means;
 2. Theapparatus of claim 1 wherein the multiple optical means are internal tothe cylinder means.
 2. image receiving cylinder means;
 3. a first lensmeans located along a first optical path which extends between saidobject data support means and said cylinder means;
 3. The apparatus ofclaim 2 wherein said cylinder means is transparent.
 3. a first lensmeans located along a first optical path Which extends between saidobject data support means and said cylinder means;
 4. a second lensmeans located along a second optical path which extends between saidobject data support means and said cylinder means, said first opticalpath and said second optical path being spaced from each other in thescanning direction along their entire lengths;
 4. The apparatus of claim1 including means to illuminate the optical object data support means ateach of the object positions.
 4. a second lens means located along asecond optical path which extends between said object data support meansand said cylinder means, said first optical path and said second opticalpath being spaced from each other in the scanning direction at saidobject data support means, at said cylinder means and at said first andsecond lens means and
 5. The apparatus of claim 1 wherein the roofreflecting member and the plane reflecting member are located onopposite sides of the lens means.
 5. means to cause relative movement inthe scanning direction a. between a document at said object data supportmeans and the ends of the optical paths thereadjacent whereby sequentialareas of the document are scanned by one of said lens means andthereafter the same sequential areas of the document are scanned by theother of said lens means and b. between said cylinder means and the endsof the optical paths thereadjacent whereby images may be projected fromsaid object data support means to said cylinder means along the opticalpaths in superposed relationship and c. reflecting means along eachoptical path including a roof mirror on one side of the lens means and amirror on the other side of the lens means.
 5. means to cause relativemovement in the scanning direction a. between a document at said objectdata support means and the ends of the optical paths thereadjacentwhereby sequential areas of the document are scanned by one of said lensmeans and thereafter the same sequential areas of the document arescanned by the other of said lens means and b. between said cylindermeans and the ends of the optical paths thereadjacent whereby images maybe projected from said object data support means to said cylinder meansalong the optical paths in superposed relationship.
 6. The apparatus ofclaim 5 wherein the roof reflecting member in one of the multipleoptical means is on the same side of the lens means as is the planereflecting member of the optical means adjacent thereto.
 7. Theapparatus of claim 6 wherein the lens means of the multiple opticalmeans are parallel with each other.
 8. The apparatus of claim 1 whereinthe lens means are skewed relative to the principal ray of the opticalmeans.
 9. The apparatus of claim 1 including means to move the lensmeans along the optical path.
 10. The apparatus of claim 1 includingmeans to move the lens means and reflecting means relative to the objectposition.
 11. The apparatus of claim 1 wherein said reflecting meansincludes a plane reflecting member and a roof reflecting member. 12.Apparatus for imaging including cylindrical object data support means;means to move the object data support means; multiple optical means eachhaving an object position on the object data support means; imagereceiving cylinder means; an image position corresponding to each of theobject positions on the cylinder means; to rotate the cylinder means;lens means determining an optical path between an object position andcorresponding image position; reflecting means along the optical path;means to align the multiple optical means for sequentially projectingportions from the object positions in superposed relationship to thecorresponding imaging positions.
 13. The apparatus of claim 12 whereinthe cylindrical object data support means for maintaining multipleobject positions and the cylinder means for maintaining multiple imagepositions are cylinders being of approximately equal diameter androtatable at approximately the same surface velocity.
 14. The apparatusof claim 13 wherein said cylindrical object data support means and thecylinder means for maintaining multiple image positions are related insize such that the radius of the cylinder means approximately equals theproduct of the object data support cylinder and the opticalmagnification of the optical means, both cylinders being rotatable atthe same angular velocity.
 15. The apparatus of claim 14 wherein theangular separation between object positions on the object data supportcylinder are equal to the angular separation of the correspondingimaging positions.
 16. Apparatus for imaging including object datasupport means; means to move the object data support means; multipleoptical means each having an object position on the object data supportmeans; image receiving cylinder means; an image position correspondingto each of the object positions on the cylinder means; means to rotatethe cylinder means; lens means determining an optical path between anobject position and corresponding image position; reflecting means alongthe optical path; means to align the multiple optical means forsequentially projecting portions from the object positions in superposedrelationship to the corresponding imaging positions; multiple imagingelectrodes interfacing with the cylinder means at the multiple imagepositions; means to couple the electrodes and the cylinder means toelectrical source means; and, means to supply photoelectrophoreticparticles between a first imaging electrode and the cylinder means. 17.The apparatus of claim 16 including means to transfer particles from thecylinder means; means to couple said means to transfer to electricalsource means of a polarity different from the imaging electrodes. 18.Apparatus for imaging including
 19. The apparatus as set forth in claim18 and further including image reflecting means along both opticalpaths.